Method and apparatus for laying down the fiber hairiness of textile yarns

ABSTRACT

The surface hairiness, or fuzziness of staple spun yarn is reduced during a sizing operation by passing individual strands of the wet sized yarn through and in contact with the surfaces of the specially designed circumferential grooves in the surface of a cylindrical roller rotating in a direction opposite to the direction of the yarn&#39;&#39;s travel so that the higher linear speed of the roller exerts a strong opposing wiping, squeezing force on the yarn moving counter to the surface speed of the inner walls of the grooves of the roller. Under certain circumstances, where modified performance is desired, the grooved roller may be rotated in the same direction as the yarn travels.

United States Patent [191 Iliman a al.

[ 51 May 15, 1973 [54] METHOD AND APPARATUS FOR LAYING DOWN THE FIBERHAIRINESS OF TEXTILE YARNS [75] Inventors: Walter F. lliman, Greensboro;Clarence R. Hyder, Burlington, both of N.C.

[73] Assignee: Burlington Industries, Inc., Greensboro, N.C.

[22] Filed: Nov. 12, 1971 [21] Appl. No.: 198,277

[52] US. Cl ..28/28, 28/726 [51] Int. Cl ..D06c 29/00 [58] Field ofSearch ..28/28, 72.6

[56] References Cited UNITED STATES PATENTS 2,402,653 6/1946 Clark..28/28 2,795,839 6/1957 Seawell ....28/28 2,996,785 8/1961 Suggs..28/28 FOREIGN PATENTS OR APPLICATIONS 574,448 3/1933 Germany .328/28Primary Examiner-Louis K. Rimrodt Attorney- Cushman, Darby & Cushman[57] ABSTRACT The surface hairiness, or fuzziness of staple spun yarn isreduced during a sizing operation by passing individual strands of thewet sized yarn through and in contact with the surfaces of the speciallydesigned circumferential grooves in the surface of a cylindrical rollerrotating in a direction opposite to the direction of the yarns travel sothat the higher linear speed of the roller exerts a strong opposingwiping, squeezing force on the yarn moving counter to the surface speedof the inner walls of the grooves of the roller.

Under certain circumstances, where modified performance is desired, thegrooved roller may be rotated in the same direction as the yarn travels.

17 Claims, 13 Drawing Figures *AMU UMAM ATTORNEYS METHOD AND APPARATUSFOR LAYING DOWN THE FIBER HAIRINESS OF TEXTILE YARNS BACKGROUND OF THEINVENTION A large variety of staple spun yarns which are used in textileweaving and knitting operations consists of a bundle of fibers whichhave been twisted together. Frequently, as is the case with staple spunyarns, the surface of the yarn is not smooth since a number of thecomponent fibers adjacent to the periphery of the yarn surface projectoutwardly from the yarn s surface. This peripheral protrusion of thefibers from the surface of the yarns can adversely affect weaving andknitting performance as the protruding fibers tend to entangle with theadjacent yarn strands which can result in binding of adjacent yarnstogether as the yarns pass through various separate restricted openingsencountered in knitting or weaving processing. As a consequence of thebinding, yarn breakage can occur which necessitates stopping theassociated knitting or weaving machine thus decreasing productionefficiency and potentially creating a quality defect. The randomprojection of fibers from a yarns surface can also result inobjectionable dragging and clinging of the yarn as it is drawn throughthe various eyes and dents of a loom. As a result, undesirable abradingor hang-ups of the yarn can occur prior to and upon entry into thesedevices, further decreasing production efficiency and increasing thepotential for reduced quality.

The advantages of laying down the peripheral fibers of a yarn in adirection opposite to that which the yarn advances through a loom havebeen long recognized and accepted. At the same time, (although up to nownever accomplished with a practical mechanism) some have reasoned andobserved that by causing the loose peripheral fibers to be helicallywrapped around the body of the yarn strand the resulting sized warp yarnexperiences the smoothest possible entry into the eyes and dents in itspassage through the loom and is free of latching and clinging that canresult in warp yarn breaks. Also undue loss of fibers from yarn isprevented.

It has also been reasoned and observed that if a sized warp yarn canhave the size applied in some manner that permits it to be moreuniformly distributed in the fiber bundle and on the yarn bundlessurface and if the voids and unevenness of distribution can be leveledout and more effectively positioned for optimum strengthening andprotection of the yarn after the size has been dried, then, not onlywill better weaving yarn be obtained but less size need be applied toachieve this advantage.

In the warp yarn slashing art, it is the usual practice to feed aplurality of moving strands of yarn continuously from a supply sourcesuch as a warp section beam to a size box holding a sizing solutionconsisting of ingredients such as starch mixed with a wax. From the sizebox, the yarns may be fed to drying apparatus consisting usually of anumber of heated cylinders. Other evaporative means may also be used.From the drying cylinders, the moving, dried, sized yarn strands aredelivered by suitable guide mechanisms to a loom beam.

To obtain a smooth yarn surface, it has been suggested previously thatrotating brushes, such as those disclosed in U. S. Pat. No. 972,760, orthe guided manipulation of warp ends be utilized to rub the yarnsagainst each other in a self-brushing action to lay down the peripheralfibers following the application of the sizing composition. However,both these arrangements have suffered from disadvantages in that thesizing solution tends to accumulate on the brushes or on devices thateffect the wiping action on the sized yarn. Also, the breakage anddoubling of yarns, when rubbed against each other, prevented theself-brushing system from receiving practical acceptance. In addition,the accumulation of sizing material on the brushes and wipers hasrequired frequent stopping of the process to effect cleaning of thesedevices from hard dried size and collected fibers. Moreover, the use ofbrushes has been found to adversely affect the quality of the yarn sincethe brushes tend to remove fibers from the yarn bundle.

Other prior art references relating to the field of the presentinvention are the U. S. Patents to Still, No. 2,565,407 of Aug. 21,1951, and Wood, No. 2,438,084 of Mar. 16, 1948.

The present invention avoids the foregoing disadvantages by theprovision of a method and apparatus for treating yarn which achieves animproved surface smoothness of the yarn in a novel way and moreefficiently than has heretofore been proposed.

Simultaneously the added advantage of size leveling action by virtue ofa squeezing force is obtained which enhances the uniformity of placementof the size in and on the fiber bundle that composes the yarn strand.

Also the yarn smoothing and size penetrating capability is augmented bya practical way to avoid size or fiber accumulation in the operation.

SUMMARY OF THE INVENTION The method of the present invention consists ofapplying a sizing solution to the yarns and then generally tangentiallypassing the yarns through the specially designed circumferential groovesof a roller which is rotated in a direction opposite, or under certaincircumstances in the same direction, as the yarn travel so that thedifferential frictional forces built up between the surface of the yarnand inner wall surfaces of the groove cause a strong opposing, wipingand squeezing force to be exerted on the yarn moving through the groove.

With this method the differential forces built up between the rotatingsurface of a grooves walls and the linear movement of the sized yarnpassing through the groove furnish a type of wiping action on theperipheral fibers projecting from the surface of the yarn strand so thatthey are caused to be drawn around the strands circumference in theformation of a helical wrap. This placement of projecting peripheralfibers is superior to the common and familiar linear smoothing down oftibers on the yarn surface in a position parallel with the axis of theyarn strand.

The direction of rotation of a grooved roll may be in the same oropposite direction to the yarn passage. Both accomplish fiber lay, withthe opposite direction roll rotation offering some preferred activityfor certain applications.

One groove is provided about the circumference of the roller for eachyarn strand being treated. Each groove has smooth, opposed, almostparallel side walls. The outermost part of the groove is slightly widerthan the base of the groove. The slight V" construction of the grooveallows different diameter yarns to self adjust to the best depth ofsurface-wiping exposure. The

width of the grooves formed by the opposing walls may vary radially fromO to 300 percent wider than the average diameter of yarn treated by thegrooved roll-device but preferably, the width near the base of eachgroove should be slightly less than the average diameter. The depth ofeach groove should be several times greater than the average diameter ofthose yarns that are to be treated by this device. In using this type ofgrooved roller, the peripheral fibers will be wrapped generallyhelically about the surface of the yarns with the longer fibersencircling the yarn strand. Simultaneously, the mild squeezing forceassures a leveling or equalizing action of the size placement in and onthe yarn.

Near the point of yarn and groove surface contact, a thin sheet of steamunder pressure is directed onto the rollers surface to cleanse groovesand prevent accumulation of size and fibers on the roller. The steam isdirected generally into the rollers grooves after the point where thesheet of warp yarns leaves the rollers grooved surface.

As an alternate to machining correctly proportioned grooves in rollermaterial, the roller may be constructed from a plurality of plateelements which when assembled on a shaft and fixed in position form therespective grooves. In either case the material of the roller may beplastic or metal or a composite of suitable material that will bedurable under constant use, resistant to corrosion and have highresistance to wear, yet be able to be machined to obtain smooth groovesurfaces.

With the method and apparatus of the present invention the peripheralfibers are more securely locked about the yarn than when the fibers arelaid down parallel to the longitudinal axis of the yarn. Moreover, byvirtue of the helical wrapping of the peripheral fibers, yarn treated bythe method of the present invention may be more easily fed through theeyes and dents of looms without concern for which direction the fibershave been laid down.

A principal object of the present invention, therefore, is to provide animproved method for smoothing the surfaces of spun yarns by helicallywrapping outwardly projecting fibers about the yarns. Another object ofthe present invention is to provide a more efficient method of treatingstaple spun yarns so that the sizing material that has been applied toit will protect it more effectively from the abusive action of the loom.A further object is to provide a method wherein the grooved roller usedfor laying down the peripheral fibers of the yarn is maintained freefrom any accumulation of sizing material or fibers. Still another objectis to provide a grooved roller device for effecting the helical wrappingof the peripheral fibers about the yarns.

Still another object of the present invention is to provide a groovedroller device for effecting an improved uniformity of size placement anddistribution in and on the filamental structure of continuousmultifilament yarns and to insure the uniform encasement of the surfacesize application on monofilament yarns.

At the same time, any undesirable broken fibers or filamentalprojections or filamental loops can be forced down onto the body of thefiber strand and be held there by the dried size. Other objects andattendant advantages of the present invention will become apparent asconsideration is given to the following detailed description andaccompanying drawings, in which:

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view ofapparatus used in one arrangement for carrying out the method of thepresent invention;

FIG. 2 is a front view in elevation, partly in section and with partsbroken away, of one embodiment and an alternate of the grooved roller ofthe present invention;

FIG. 3 is a greatly enlarged detail view of a portion of theconventional staple yarn prior to its treatment by the method of thepresent invention;

FIG. 4 is the same view of the yarn of FIG. 3 after treatment inaccordance with the principles of the present invention;

FIG. 5 is a side view of a section of one of the grooves of the rollerwith a single strand of yarn passing therethrough;

FIG. 6 is an enlarged diagrammatic illustration of the wiping forcesimparted to the peripheral fibers of the yarn strand as it passesthrough a groove of a roller;

FIGS. 7-11 inclusive are end views of a cross section of a strand ofyarn as it enters, passes through and leaves a groove of the roller; and

FIGS. 12 and 13 are diagrammatic illustrations of the forces effectingthe wrapping of the fibers about a yarn strand.

DETAILED DESCRIPTION OF THE INVENTION Referring now to the drawings,there is illustrated in FIG. 1, in schematic form, an arrangement of ayarnslashing apparatus which consists of a size box 10 containing asizing solution 12. An immersion roller 14 is located in size box 10 andserves to immerse running sheets or webs of yarn 18 into the sizingsolution. A plurality of yarns may be fed from a suitable number of warpsection beams (not shown) into the size box 10. It should be understood,of course, that a plurality of treatment solutions may be utilized insequence. From the immersion roller 14, the webs are delivered tosqueeze rolls 16. The squeeze rolls 16 may be driven by gears or othersuitable means of conventional design, while the immersion roller 14 maybe free-running or driven. It will be understood that any desired numberof yarns may be fed into the size box 10 in the form of a sheet ofparalleled yarns as is conventionally done in the textile warp sizingprocess.

From the squeeze rolls 16, the yarns may pass over a single groovedroller or may be divided into a plurality of incremental sheets 19, eachof which is then passed over the specially grooved rollers 20. Eachgrooved roller is rotated by conventional means, such as belts 21 orgears driven by an electric motor 23, preferably in a direction oppositeto the direction of yarn travel. If found desirable, the grooved rollersmay be rotated in the same direction as the direction of yarn passagethrough the grooves. In such circumstances the grooved roller would berevolved at a peripheral speed that would offer a differential betweenthe linear speed of the grooves wall surfaces and the linear speed atwhich the yarn passes through the grooves of each roller. Thisdifferential in moving rates is necessary to establish the frictionalwiping drag of opposing forces. This action, as with the roll rotated ina direction opposite to the direction of the yarn, is accompanied by adesirable squeezing force applied to the sized yarn passing through thegrooved region.

Contact of the wet yarn with the grooves of each roller may tend tocause the wet size material and loose fibers to accumulate in a rollersgrooves. To prevent such build-up and a resultant detrimental sizecondition being picked up on the yarn, slotted steam tube applicators 22are positioned closely adjacent to each roller 20 to direct a jet ofsteam under pressure against an area of the rollers surface immediatelyfollowing the region where the yarns are pulled out and away from thegrooves. The steam jet should be directed generally into the grooves todeeply penetrate them to prevent size material and loose fibers fromaccumulating and developing into hard particles which might bedetrimental if redeposited onto the yarn. The steam may be supplied fromconventional means such as a steam generatorindicated at 24 which isconnected by suitable conduits 26 to the applicators 22. To avoidundesirable steam condensation in the line, it will be necessary toprovide suitable traps in the steam lines and insulation on these lines.

From the rollers 20, the yarn sheets are passed over or through suitabledrying means such as an appropriate number of rotary drying cylinders 28of conventional design. In the FIG. 1 drawing, the drying phase is onlysuggested by showing yarns from different grooved rolls passing onto oneaccumulating drying cylinder. In practice, it is preferable to dry thesized and fiber lay roll treated yarn in a manner that allows the yarnfrom each grooved roller to be given the widest practical placementacross the drying cylinder surface to assure that adjacent yarns avoidtouching each other during the evaporative drying phase of treatment.Following the drying the yarn moves from the heated cylinders to take-uploom beams (not shown).

Referring now to FIG. 2, there is illustrated a detailed view of oneembodiment of the rollers 20 of the present invention. The rollersconsist of a generally cylindrical body made from a suitable plastic,metal or composite material into the surface of which are machined aplurality of circular grooves, examples of which are generallydesignated at 30. In an alternate embodiment as illustrated in theright-hand portion of the roller illustrated in FIG. 2, the rollerconsists of a plurality of discs, one of which is indicated at 32, whichare formed with a central aperture as at 34 and provided with a notch36. With this arrangement, when the discs 32 are mounted on a shaft 38,as illustrated in FIG. 2, the adjacent tapered outer edges of each discwill define the grooves 30. A key member 40 is utilized to firmly fixthe discs on the shaft 38 for non-slipping rotation therewith.

The grooved rollers constructed with the desired number of grooves perinch of length are mounted on the shaft 38 and held in position on thisshaft by retaining nuts 50 which are tightened on the shafts twothreaded surfaces 48. Washers 52 may be interposed between the ends ofthe grooved roller and the retainer nuts 50.

In still another embodiment, the machined grooved rollers may be madefrom round bar stock. A grooved structure can be formed with alternatewasher-like wafers which are slipped onto a supporting shaft. Byalternating washers with slight differences in diameter, a groovedformation can be obtained wherein the smaller diameter washers will formthe base of the grooves with the adjacent larger diameter washersforming the adjoining side walls of the groove.

Utilization of segmented grooved rollers, in which the multiple segments(approximately 6 to 10 units) would be clamped together on a commonshaft to assemble the full length grooved roller, or by using groovedrollers assembled from a series of disc segments clamped together toform the completed roller will avoid the necessity of replacing anentire roller in the event that one of the grooved portions becomesdamaged. Additionally, the roller may be readily adapted to handle anyyarns from very coarse to very fine dimensions simply by substitutingappropriately dimensioned groove-forming elements on the supportingshaft as needed.

It is desirable that the material from which the grooved rollers areconstructed be highly resistant to wear and structurally stable whensubjected to heat, water and the chemicals used in the sizing solution,and yet be able to be machined or otherwise fabricated to produce smoothwall surfaces for the grooves. Acetal resin plastics, for example, havebeen found to perform effectively in the environment to which thepresent invention pertains.

Referring now to FIG. 3, there is illustrated a section of conventionalspun yarn 54, a number of fibers of which project outwardly in a randommanner from the peripheral surface of the yarn as at 56. This is thecondition of the yarn prior to its contact with the grooved rollers 20of the present invention. In FIG. 4, there is schematically illustratedthe condition of the same piece of yarn subsequent to its treatment bythe process and apparatus of the present invention. The outwardlyprojecting fibers 56 have been wrapped helically above the surface ofthe yarn strand and are securely held in place by virtue of the helicalwrapping and the drying of the size material. It has been determinedthat the more rapidly the grooved roller is rotated, when the yarn ispassing through the grooves in the direction opposite to the rollersrotating direction, the more transversely to the longitudinal axis ofthe yarn strand are the peripheral fibers 56 wrapped.

A description now will be given with the aid of FIGS. 5-13 inclusive, ofthe manner in which the rotating surfaces of a groove 30 effect thehelical wrapping of the peripheral fibers about an individual yarnstrand.

In FIG. 5, a single strand of yarn 58 is being passed through a groove30 which is a sectional view of one groove of the roller 20 with theline at 60 designating the base of the groove and the numeral 62designating one of the walls of the groove, the opposite wall beingbroken away to more clearly show the position of the yarn in FIGS. 7-11inclusive. FIG. 6 is a greatly enlarged illustration of the passage ofthe yarn strand 58 through a groove 30 with the arrows indicated at 64representing the generally downwardly and backwardly directed wipingforces that are imparted to the peripheral fibers of yarn 58 during theinitial stages of its passage through the groove 30. The arrowsindicated at 66 represent the generally upwardly and backwardly directedwiping forces imparted to the peripheral fibers by the side walls of thegroove 30 as the yarn passes out of the groove and past the roller. Itwill be understood, of course, that in the region designated as 68 thewiping forces imparted by the surfaces of the groove 30 are generallybackward and parallel to the direction of travel of the yarn. In FIGS.7-11 inclusive, there are shown the progressive steps of the passage ofthe yarn through a groove when viewed into the cross section of thelongitudinal axis of the yarn strand 58. In FIG. 7, a section of theyarn begins entrance into the groove so that as the section of yarnpasses to the position illustrated in FIG. 8, the generally downwardlyand backwardly directed wiping forces corresponding to the arrows 64 inFIG. 6 will predominate to lay down the peripherally projecting fibers.When the yarn section passes through the positions illustrated in FIGS.8, 9 and 10, not only does the wiping action of the grooved surfacescontinue to lay down the peripherally projecting fibers, but the body ofthe yarn is subjected to a squeezing action enabling the size solutionto be leveled uniformly throughout the yarn strand. In this embodiment,the inner half of the depth of the grooves gradually decreases in widthfrom the midpoint of the groove which is equal to or slightly less thanthe average diameter of the yarn being treated. The squeezing actionwill displace any air pockets in the fibers and will effect morethorough and uniform penetration and placement of the size among theyarns fibers. In addition, the excess size solution that is squeezed outof the yarn strand as the yarn strand passes through the positionsillustrated in FIGS. 8-10, will exert a dragging force due to itsviscous and cohesive character on the peripheral fibers since the sizesolution will be acted on in one direction by the surfaces 62 and 63 ofthe groove, and in the opposite direction by the moving yarn stranditself. As a result, the projecting fibers on the top surface of theyarn 58 which would not come in contact with a portion of the groovesurfaces will also be laid down on the surface of the yarn strand.

It has been found that with a roller having a threeinch radius which isrotated at 110 revolutions per minute and with the yarn passing in adirection opposite to the direction of rotation of the roller at a rateof 16 yards/minute, a satisfactory helical wrapping of the peripheralfibers is obtained. As illustrated in FIG. 12, it is clear that as theyarn enters, the forces are generally downwardly and backwardly directedas represented by the arrows in FIG. 12, and while the yarn leaves thegroove of the roller, the forces would be in the opposite direction tothe arrows shown in FIG. 12. It is believed that the helical wrappingwhich is illustrated schematically by the arrows in FIG. 13 is achievedas a result of a whip effect imparted to the peripheral fibers inconjunction with the dragging force which results from the presence ofthe excess sizing solution. As previously noted, it has been found thatthe greater the speed of rotation of the grooved roller relative to thepassage of the yarn through the grooves, the more transversely are theperipheral fibers wrapped about the body of the yarn strand.

It has also been found that when a warp of staple spun yarn strands aretreated by the method and apparatus of the present invention, a moreintimate bonding between the sizing solution and fibers of the yarn isobtained, thus affording improved protection of the yarn duringsubsequent weaving or other textile operations.

While the foregoing describes the preferred embodiments of the methodand apparatus of the present invention it will be understood thatvarious modifications may be made in the dimensions and arrangement ofthe parts without departing from the spirit of the invention or thescope of the appended claims. For example, although emphasis has beenplaced on rotation direction of the grooved rollers being opposite todirection of yarn passage, for certain reasons it may be more desirableto have the rollers turn in the same direction as the yarn, even if withlesser effectiveness in forcing peripheral fibers about the yarnssurface to be anchored in the size.

What is claimed is:

l. A method of treating spun yarn having a predetermined averagecross-sectional diameter and composed of fibers at least some of whichproject in random fashion outwardly from the periphery of the yarnsurface, said method comprising the steps of:

applying a sizing solution to the yarn,

generally tangentially passing the yarn through and in contact with thesmooth surfaces of a groove formed about a circumference of a rotatingroller, the width dimension of the groove being such that said yarn issubjected to a compressive force during at least a portion of the yarnspassage through the groove and the depth dimension of the groove beinggreater than the largest cross-sectional diameter of the yarn,

rotating said roller about its longitudinal axis at an angular velocitysuch that the surfaces of the groove move at a linear velocity thatresults in a differential between it and the velocity with which theyarn passes through the groove to impart a resistive drag to theprojecting fibers whereby the randomly projecting fibers will behelically wrapped about the yarns surface;

and subsequently drying the yarn.

2. The method as claimed in claim 1 including the step of rotating theroller in a direction opposite to the direction of travel of the yarnthrough the groove.

3. The method as claimed in claim 1 including the step of rotating theroller in a direction the same as the direction of travel of the yarnthrough the groove.

4. The method as claimed in claim 1 including the step of cleaning thegroove surfaces by continuously directing a sheet of vapor, underpressure and substantially free of liquid condensate, against therollers surfaces in a region following the point at which the yarnleaves the groove.

5. The method as claimed in claim 4 wherein said vapor is steam.

6. The method as claimed in claim 1 wherein a plurality of yarns aretreated and a corresponding plurality of said grooves are provided onsaid roller.

7. The method as claimed in claim 6 including the step of providing aplurality of grooved rollers.

8. The method as claimed in claim 7 including the step of rotating eachroller in a direction opposite to the direction of travel of yarnsthrough the respective grooves.

9. The method as claimed in claim 7 including the step of rotating eachroller in a direction the same as the direction of travel of yarnsthrough the respective grooves.

10. The method as claimed in claim 8 including the step of continuouslydirecting a stream of vapor under pressure and substantially free ofliquid condensate against the surfaces of each roller in a regionfollowing the point at which the yarns leave their respective grooves toclean the respective groove surfaces.

11. In an apparatus for treating a plurality of spun yarns includingsize-applying means, yarn-drying means and means for transporting theyarns from said size-applying means to said drying means, said yarnsbeing of the type having generally circular cross sections of apredetermined average cross-sectional diameter, the improvementcomprising a substantially cylindrically shaped roller having aplurality of circumferentially formed, smooth-surfaced grooves evenlyspaced along the longitudinal axis thereof, each groove having a depthgreater than said diameter and width which varies uniformly from thebase thereof to the rim such that at least a radially inwardmost portionof each groove has a width that is less than said diameter, said rollerbeing disposed between said size-applying means and said drying meanswith its longitudinal axis generally transverse to the direction oftravel of said yarns, and means for rotating said roller about itslongitudinal axis.

12. The apparatus as claimed in claim 11 wherein said portion of each ofsaid grooves having a width less than said diameter of said yarn extendsfrom the base of each groove to approximately half of the depth thereof.

13. The apparatus as claimed in claim 11 wherein the depth of each ofsaid grooves is between four and five times greater than said diameterof the yarn.

14. The apparatus as claimed in claim 11 wherein said roller comprises aplurality of circular plate segments each having a central aperture forreceiving a shaft, each of said plate segments being formed with acentral disc portion of predetermined radius, the surface portions ofsaid plate segments beyond said disc portions being tapered toward eachother so that when said plate segments are fixed on a shaft the spacesexisting between said tapered portions will define said grooves of saidroller.

15. In an apparatus for sizing a plurality of spun yarns includingsize-applying means, yarn-drying means and means for transporting theyarns from said sizeapplying means to said drying means, said yarnsbeing of the type having generally circular cross sections of apredetermined average diameter, the improvement comprising asubstantially cylindrically shaped roller having a plurality ofcircumferentially formed, smoothsurfaced grooves evenly spaced along thelongitudinal axis thereof, each groove having a depth between four andfive times greater than said average diameter of said yarns and a widthwhich varies uniformly from the base thereof to the rim such thatapproximately the radially inward half of the depth of each groove has awidth that is less than said yarn diameter, said roller being disposedbetween said size-applying means and said drying means with itslongitudinal axis generally transverse to the direction of travel ofsaid yarns, and means for rotating said roller about its longitudinalaxis in a direction opposite to the direction of yarn travel.

16. The apparatus as claimed in claim 11 wherein a plurality of saidrollers are provided disposed between said size-applying means and saiddrying means.

17. The apparatus as claimed in claim 16 wherein means are provided fordirecting a stream of vapor under pressure against the surface of eachroller in a region following the point at which the yarns leave theirrespective grooves to clean the respective groove surfaces.

1. A method of treating spun yarn having a predetermined averagecross-sectional diameter and composed of fibers at least some of whichproject in random fashion outwardly from the periphery of the yarnsurface, said method comprising the steps of: applying a sizing solutionto the yarn, generally tangentially passing the yarn through and incontact with the smooth surfaces of a groove formed about acircumference of a rotating roller, the width dimension of the groovebeing such that said yarn is subjected to a compressive force during atleast a portion of the yarn''s passage through the groove and the depthdimension of the groove being greater than the largest cross-sectionaldiameter of the yarn, rotating said roller about its longitudinal axisat an angular velocity such that the surfaces of the groove move at alinear velocity that results in a differential between it and thevelocity with which the yarn passes through the groove to impart aresistive drag to the projecting fibers whereby the randomly projectingfibers will be helically wrapped about the yarn''s surface; andsubsequently drying the yarn.
 2. The method as claimed in claim 1including the step of rotating the roller in a direction opposite to thedirection of travel of the yarn through the groove.
 3. The method asclaimed in claim 1 including the step of rotating the roller in adirection the same as the direction of travel of the yarn through thegroove.
 4. The method as claimed in claim 1 including the step ofcleaning the groove surfaces by continuously directing a sheet of vapor,under pressure and substantially free of liquid condensate, against theroller''s surfaces in a region following the point at which the yarnleaves the groove.
 5. The method as claimed in claim 4 wherein saidvapor is steam.
 6. The method as claimed in claim 1 wherein a pluralityof yarns are treated and a corresponding plurality of said grooves areprovided on said roller.
 7. The method as claimed in claim 6 includingthe step of providing a plurality of grooved rollers.
 8. The method asclaimed in claim 7 including the step of rotating each roller in adirection opposite to the direction of travel of yarns through therespective grooves.
 9. The method as claimed in claim 7 including thestep of rotating each roller in a direction the same as the direction oftravel of yarns through the respective grooves.
 10. The method asclaimed in claim 8 including the step of continuously directing a streamof vapor under pressure and substantially free of liquid condensateagainst the surfaces of each roller in a region following the point atwhich the yarns leave their respective grooves to clean the respectivegroove surfaces.
 11. In an apparatus for treating a plurality of spunyarns including size-applying means, yarn-drying means and means fortransporting the yarns from said size-applying means to said dryingmeans, said yarns being of the type having generally circular crosssections of a predetermined average cross-sectional diameter, theimprovement comprising a substantially cylindrically shaped rollerhaving a plurality of circumferentially formed, smooth-surfaced groovesevenly spaced along the longitudinal axis thereof, each groove having adepth greater than said diameter and width which varies uniformly fromthe base thereof to the rim such that at least a radially inwardmostportion of each groove has a width that is less than said diameter, saidroller being disposed between said size-applying means and said dryingmeans with its longitudinal axis generally transverse to the directionof travel of said yarns, and means for rotating said roller about itslongitudinal axis.
 12. The apparatus as claimed in claim 11 wherein saidportion of each of said grooves having a width less than said diameterof said yarn extends from the base of each groove to approximately halfof the depth thereof.
 13. The apparatus as claimed in claim 11 whereinthe depth of each of said grooves is between four and five times greaterthan said diameter of the yarn.
 14. The apparatus as claimed in claim 11wherein said roller comprises a plurality of circular plate segmentseach having a central aperture for receiving a shaft, each of said platesegments being formed with a central disc portion of predeterminedradius, the surface portions of said plate segments beyond said discportions being tapered toward each other so that when said platesegments are fixed on a shaft the spaces existing between said taperedportions will define said grooves of said roller.
 15. In an apparatusfor sizing a plurality of spun yarns including size-applying means,yarn-drying means and means for transporting the yarns from saidsize-applying means to said drying means, said yarns being of the typehaving generally circular cross sections of a predetermined averagediameter, the improvement comprising a substantially cylindricallyshaped roller having a plurality of circumferentially formed,smooth-surfaced grooves evenly spaced along the longitudinal axisthereof, each groove having a depth between four and five times greaterthan said average diameter of said yarns and a width which variesuniformly from the base thereof to the rim such that approximately theradially inward half of the depth of each groove has a width that isless than said yarn diameter, said roller being disposed between saidsize-applying means and said drying means with its longitudinal axisgenerally transverse to the direction of travel of said yarns, and meansfor rotating said roller about its longitudinal axis in a directionopposite to the direction of yarn travel.
 16. The apparatus as claimedin claim 11 wherein a plurality of said rollers are provided disposedbetween said size-applying means and said drying means.
 17. Theapparatus as claimed in claim 16 wherein means are provided fordirecting a stream of vapor under pressure against the surface of eachroller in a region following the point at which the yarns leave theirrespective grooves to clean the respective groove surfaces.